Þorgerður Brák was Egil's nursemaid, thought to be a Celtic slave. In one of the more dramatic moments in Egil's Saga, she heroically saves Egil's life (from an attempted crime of passion, by his own father, Skallagrímur Kveldúlfsson), and jumps into the sea to escape the enraged Skallagrímur. Today a sculpture marks a spot near where she leapt, ultimately to her death: Skallagrímur hit her with a stone, and she never emerged from the water again.
The strait she swam, between Borgarnes and the islet offshore, is named Brákarsund for her. The town celebrates an annual festival in her honour.